1. Field
Embodiments of the present disclosure relate to ultrasound probes emitting ultrasound to an object and receiving echo ultrasound reflected by the object, and methods of controlling the same.
2. Description of the Related Art
Ultrasound diagnostic apparatuses non-invasively generate an image of a target region inside an object such as a soft tissue tomogram or a blood stream tomogram by irradiating ultrasonic signals generated by transducers of a probe toward the target region from the surface of the object and receiving reflected ultrasonic signals (ultrasonic echo signals). Thus, the ultrasound diagnostic apparatuses have been used for medical purposes, for example, to examine the inside of the object, detect impurities, and measure injury.
Since ultrasound diagnostic apparatuses are small and inexpensive, display an image in real time, and provide high safety without causing X-ray exposure, as compared to other diagnostic imaging apparatuses, such as X-ray diagnosis apparatuses, computed tomography (CT) scanners, magnetic resonance imaging (MRI) apparatuses, and nuclear medicine diagnosis apparatuses, the ultrasound diagnostic apparatuses have been widely used with other diagnostic imaging apparatuses.
Particularly, a three-dimensional (3D) ultrasound imaging apparatus generates a 3D ultrasound image and visualizes the generated 3D image on a display apparatus by acquiring 3D data of an object by using a probe, or the like, and volume-rendering the acquired 3D data.
In order to realize an image by using an ultrasound diagnostic apparatus, a unit and/or device that perform interconversion between ultrasound signals and electric signals are required. In this regard, the unit and/or device are referred to as an ultrasound probe or ultrasound transducer.
In general, an ultrasound probe includes an ultrasound module including a piezoelectric layer to perform interconversion between electric signals and sound signals while a piezoelectric material vibrates, a matching layer to reduce a difference in acoustic impedance between the piezoelectric layer and a human body thereby efficiently transferring ultrasound generated by the piezoelectric layer to a target region of the human body, a lens layer to focus ultrasound proceeding forward from the piezoelectric layer to a predetermined point, a backing layer to block transmission of the ultrasound proceeding backward from the piezoelectric layer thereby preventing image distortion. Most medical ultrasound probes commonly used in the art include a plurality of ultrasound devices, except or medical ultrasound probes for special use including a single ultrasound device.
Such medical ultrasound probes are classified according to various standards such as number of ultrasound devices, alignment type of ultrasound devices, shape of alignment axis ultrasound devices, or applications thereof. The medical ultrasound probes may be classified into a single device-type ultrasound probe and a multi device-type ultrasound probe based on the number of ultrasound devices. In this regard, the multi device-type ultrasound probes may be classified into one-dimensional (1D) array-type ultrasound probes in which ultrasound devices are arranged in one axis and two-dimensional (2D) array-type ultrasound probes in which ultrasound devices are arranged in a plurality of axes to cross each other, based on the alignment type of ultrasound devices.
In recent years, an ultrasound probe capable of realizing a 3D image, particularly, a 3D dynamic image, of the inside of the human body has been required. 3D images may be realized by using an ultrasound diagnostic apparatus by rotating a transducer in addition to using conventional 1D array-type and 2D array-type ultrasound probes.
Conventionally, when a 3D image is generated based on signals from a sensor acquired while an ultrasound device of an ultrasound probe wobbles, there is no separate mechanical device for compensating errors. Accordingly, as a rotation angle of a motor changes with time, a backlash is caused after a predetermined delay. The backlash is a change in a swing angle of a swing motion, in which an alignment axis of an ultrasound device moves in a predetermined angle. The backlash is a delay occurring when a rotational motion of a motor is transferred to an alignment axis of an ultrasound transmitting and receiving device.
In this regard, blurring of an ultrasound image occurs in some regions due to the backlash of a clockwise CW image received in the clockwise direction of the ultrasound probe and a counter clockwise CCW image received in the counter clockwise direction thereof.